Author Archive

The cover photograph was taken by Cristina Poetto in Tafí del Valle, Argentina

Jorge J. Casal and co-workers explain why some long-day plants flower earlier when daylight hours are long (like in the spring or summer) while short-day plants flower earlier when daylight hours are short (for example in the autumn or winter). These different classes of photoperiodic response can be observed among different species and in some cases within a given species.

The Argentinian team led by Casal explored the mechanism controlling levels ofproteins such as Flowering Locus T (FT) , Constans (CO) and others. They conclude that “the existence of multiple pathways with contrasting photoperiodic effects on flowering time within a single species, suggests that the photoperiodic behaviour of plants results, at least in part, from the net balance of positive and negative effects of photoperiodic conditions on multiple regulatory pathways”.

Scientists from China, the US and Peru claim to have successfully treated late-stage breast cancer patients using laser immunotherapy to stimulate patients’ own immune systems to fight the cancer.

Wei Chen from the University of Central Oklahoma and colleagues used laser immunotherapy to treat 10 patients from Peru, aged 36 to 85, considered to be out of other treatment options. Tumour metastasis – when the cancer spreads from one part of the body to another – is the major cause of treatment failure for cancer patients, says Chen. Initial results of this pre-clinical study have shown that it can reduce primary tumours and metastases with fewer side effects than traditional treatments.

The team injected a light-absorbing agent into the patient’s body and directed non-invasive laser radiation onto the area – the interaction between the two heats up the target tissue. This doesn’t result in complete destruction of the tumour cells, but it can cause the cells to swell and break down, which stimulates an immune response. Then they injected an immunoadjuvant into the centre of the tumour, which enhances the immune response. They studied the effects over a year using biopsies and medical imaging.

Laser irradiation can be used to stimulate patients' own immune systems to fight cancer

They found that the laser therapy ‘induced positive responses in most patients, including reduction, and in some cases eradication, of treated primary tumours as well as reduction, again in some cases eradication, of untreated metastatic tumours,’ says Chen. ‘So far, none of the patients who stayed in our trials has died,’ he adds.

The therapy is nontoxic, tolerated well by patients and no harsh side effects were observed, apart from local reactions such as pain, redness, swelling and skin blistering caused by the heat of the laser, but these healed quickly.

Mladen Korbelik from the British Columbia Cancer Agency and the University of British Columbia, both in Vancouver, Canada, thinks that the work is ‘highly innovative and potentially groundbreaking’. However, he says that the mechanism is yet to be fully elucidated. He suggests that ‘it appears to involve a presentation of multiple tumour antigens in the fashion of an autologous cancer vaccine [vaccines that contain inactivated tumour cells to elicit an immune response]‘. Tailoring the antitumour action to individual patients, similar to photodynamic therapy-generated vaccines, elicits a strong immune response directed specifically at the patient’s tumours, he adds.

Chen plans to apply to the US Food and Drug Administration for approval to conduct human trials in the US. ‘We plan to develop laser immunotherapy into a mainstream, worldwide therapy,’ he says, adding that he hopes to use it for other cancer types such as melanoma, lung, prostrate and colorectal cancers. ‘Another goal is to introduce the therapy to developing countries, since the therapy only requires simple facilities and equipment,’ he concludes.

Taken from a Chemistry world story written by Elinor Richards on the 4th March 2011

Welcome to 2011, Photochemical & Photobiological Sciencesissue 1 is now live and we are officially celebrating our 10th year of publication.

In our first issue of 2011, the Editors reflect on the highlights for the journal. Photochemical & Photobiological Sciences (PPS) has published excellent themed issues in the past and they have been highly downloaded and cited. Recent themed issues published in 2010 are:

If you know someone who has made a significant contribution to advancing the chemical sciences why not nominate them for one of our prizes or awards.

The RSC currently presents around 60 prestigious Prizes and Awards annually to scientists in all the main chemical science disciplines allowing for the greatest range of scientists to be recognised for their work; individuals, teams and organisations working across the globe.

There are nine categories of awards including specific categories for Industry and Education so whether you work in business, industry, research or education recognition is open to everyone.

Our Prizes and Awards represent the dedication and outstanding achievements in the chemicals sciences and are a platform to showcase inspiring science to gain the recognition deserved.

The current themed issue gathers the communications presented at the meeting on “Ciamician–Paternò heritage. Photosciences: a look into the future”, held in Ferrara, Italy, July 16–17, 2010. The participants at the meeting discussed their views on the future of photochemistry. Those are captured in this themed issue (two more perspectives will appear in future issues of PPS). We would like to thank Angelo Albini, University of Pavias, Italy, who guest edited this issue.

With an average of 96 days from manuscript receipt toadvanced on-linepublication, Photochemical and Photobiological Sciences (PPS) is faster than its main competitors: Photochemistry and Photobiology (PP), Journal of Photochemistry and Photobiology A: Chemistry (JPPA) and Journal of Photochemistry and Photobiology B: Biology (JPPB).

Take advantage of these fast processing times and submit your work to Photochemical & Photobiological Sciences today!

We would like to take this opportunity to thank our authors and referees for their hard work and help in making Photochemical and Photobiological Sciences the fastest journal publishing the latest developments in photochemistry and photobiology.

In their editorial, the guest editors explain that “Pigments all either use vitamin A aldehyde (retinal) as their chromophore, thus allowing the absorption of light, or contain vitamin A derivatives as the base of their structure. The structure, function and evolution of rhodopsins are discussed in several reviews and papers.

The fate of the retinal chromophore on the absorption of light is covered in another.

Bistable rhodopsins such as melanopsin and parapinopsin are also reviewed. In addition, a method for quantitative measurements of the light-induced body color change in zebrafish larvae is discussed. Several papers address the bis-retinoids of the retina, particularly A2E, which is an important aging topic. The carotenoid binding proteins,which are also likely to be of clinical relevance, are also reviewed. ”

US scientists have in vivo evidence that sunlight could be one of the factors leading to age-related macular degeneration (AMD) which is the principal cause of blindness in the elderly.

The etiology of AMD is often associated with aging, smoking, a high-fat diet, genetics and gender. There have also been several debates about whether sunlight is an environmental factor causing AMD, however previous studies have failed to confirm this relationship.

In the study published in Photochemical & Photobiological Sciences, Wielgus et al. showed that blue light exposure promotes the oxidation of A2E and iso-A2E in the rats’ eyes leading to phototoxicity in the retinal cells. A2E is a functional group present in lipofuscin, a fluorescent material which demonstrates the first signs of macular degeneration in the retinal cells. When one gets older, the level of A2E, a bis-retinaldehyde-phosphatidylethanolamine, increases in the retinal cells.

Cross section images of the retinas isolated from the rats exposed to blue light or housed in the dark for 6 h. The retinas were evaluated immediately after light exposure. Pyknotic nuclei in the ONL and disorganization of photoreceptor inner and outer segments were the earliest retinal changes that were observed.

The exact structure(s) of photo-oxidised A2E have yet to be determined but they were found to cause extensive damage to the retina. This study suggests that a similar effect may also be taking place in human eyes.

Our latest themed issue on Photofunctional proteins: from understanding to engineering, is now online. The issue was guest edited by Professors Aba Losi, Cristiano Viappiani and Santi Nonell.

It contains various topics such as optogenetics where light-gated proteins originally designed by nature, also known as photoreceptors,are exploited as tools to elegantly photomodulate cell activities. Other topics cover fluorescent proteins and its applications in genetic engineering. Fluorescent proteins have revolutionized the field of molecular biology and in fact this was recognized with the 2008 Nobel Prize awarded to the pioneers in the field Osamu Shimomura, Martin Chalfie and Roger Y. Tsien.

We hope that you will find this themed issue on photofunctional proteins an enjoyable read.

Fernández-Ibáñez and co-workers showed that F. equiseti chlamydospores in distilled and simulated municipal wastewater effluent were inactivated with 10 mg L−1 of H2O2 in a 60 L CPC photoreactor. They explained that the use of low concentrations of hydrogen peroxide and CPC systems may be a good alternative for disinfection of resistant microorganisms in water.

Download the full article here. This paper is published as part of the themed issue of contributions from the 6th European Meeting on Solar Chemistry and Photocatalysis: Environmental Applications held in Prague, Czech Republic, June 2010.